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利用各种实验手段对Ni52 Mn2 4 Ga2 4 单晶中马氏体变体的择优取向进行了表征 .针对金相观察、磁场干预的相变应变、磁感生应变等实验结果 ,分析了马氏体相变过程变体自发择优取向和磁诱导择优取向的机理 .根据不同方向磁场干预相变应变的结果 ,计算了Ni52 Mn2 4 Ga2 4 单晶中等效取向内应力的大小约为 2 .4 5MPa .从变体择优取向造成的有效弹性和磁畴分布两个方面 ,对单晶样品在 [0 0 1]和 [0 10 ]两个等价的晶体学方向上磁感生应变特性的差别 ,包括最大应变值、饱和场、滞后效应和起始磁场数值的参数 ,进行了分析和讨论 .
The preferred orientation of martensite in Ni52Mn2 4 Ga2 4 single crystal was characterized by various experimental methods.According to the experimental results of metallographic observation, phase-change strain induced by magnetic field and magnetic induction strain, The mechanism of the spontaneous preferred orientation and the magnetically induced preferred orientation in the bulk phase transformation process are discussed.According to the results of phase transformation strain in different directions, the equivalent orientation internal stress in Ni52 Mn2 4 Ga2 4 single crystal is calculated to be about2.45 MPa From the aspects of effective elasticity and magnetic domain distribution caused by the preferred orientation of the variant, the difference of the magnetic induced strain in the two equivalent crystallographic directions of [0 0 1] and [0 10] The parameters including the maximum strain, saturation, hysteresis and initial magnetic field are analyzed and discussed.